I just picked up a new (to me) truck. Its a 2001 Chevy Silverado 1500HD with the 6.0 liter engine. Has anyone had any luck with improving the fuel economy with this size engine? I'm currently getting about 12.2 mpg's on the highway and I wouldn't mind making a few slight mods to the truck if I could bump it up into the 14-15mpg range. Thanks!!

WOW you only get 12.2 on the highway . sounds like somethings wrong.i have a 05 ford 6.0 and get 19-20 mpg on the highway and 16-17 in town. most of the people i know with chevys say they get better mpg than ford.how many miles on your truck? everyone i've talked to wether it be dodge ,chevy.ford or others say they get better mpg with a chip or programmer as long as they don't use the power.if they get into it mpg goes down.

I've heard the GM 6.0 is a gas hog but that sounds pretty bad. What speed are you traveling at? I can get 20+ @ 60 MPH in my 5.7L Dodge 1/2 ton and 18-19 @ 70-75.

Going slower will probably net you more savings (money and gas) than any modification you could do.

Intake, exhaust and an appropriate retune would save some gas if you can stay light on the pedal but I doubt it would net you any real savings.

Have you gone through the basics? Clean air filter, check spark plug gaps? How many miles are on it? If more than 75k or so it could be time to replace at least the front O2 sensors (The ones that control AFR, not the rear ones which usually just monitor emissions).

Jeff,
I average about 70-75 on the highway, I'm pretty good about keeping my foot off the pedal, and rarely ever gun it. I haven't really had a chance to run through the basics on it except for regular maintenance. The truck just rolled over 109K a few days ago.

NuBu,
Have you had any experience with this truck/motor combo? I agree, I think getting 15mpg would definitely be a stretch. As for towing, I'm coming from a little worn out 4.8L silverado, so just about anything would be an improvement.

Yes I've had almost every chevy motor ever offered in a truck, whether in a personal or work truck. The only motor I haven't had in a truck is the 8.1. The 6.0 is a much better motor for towing than the 4.8 or 5.3. The mileage isn't to great though, but hey it's a truck. I wouldn't waste your money trying to get better mileage out of it, you'll never get it high enough to make it worth the initial cost. You'd be better off spending the dough on gas., make sure the truck is in good mechanical condition, and just enjoy it. Keep your foot out of it as much as you can, that's your only saviour. The 6.0 is a good motor.

2004 escalade esv 6.0 and AWD here, surprisingly daily driving i get around 14mpg, that is a mixed city and highway and an amazing 17mpg on trips to vegas!! lol, but then again the drive is pretty flat with no hills.

The Denali or the Escalade doesn't have the same 6.0 that the OP has. The denali was a modded LQ4 which had a little more HP and TQ. The excalade was the LQ9, pretty different than the LQ4. Could be the difference in your mileage. I had the LQ9 in a silverado SS and it got 17 mpg.

The Denali or the Escalade doesn't have the same 6.0 that the OP has. The denali was a modded LQ4 which had a little more HP and TQ. The excalade was the LQ9, pretty different than the LQ4. Could be the difference in your mileage. I had the LQ9 in a silverado SS and it got 17 mpg.

With ECM tuning you can get the LQ9 very close to the stock LQ4. Remember the LQ4s are tuned from the factory to run Premium-the LQ9s are not. I've had a Westers 93 Octane Hot Tune in my 2003 Sierra Denali for the last 6 years. He does offer tunes for mileage as well. The changes that he makes to firm up transmission shift points make a huge difference in how quickly the truck kicks down when you want power.

You have it backwards. If you tuned the LQ9 to be close to the LQ4 you would be going down in power. The LQ9 has a higher compression ratio than the LQ4 does, you can't program that. I am fairly familiar with ECM tuning.

You have it backwards. If you tuned the LQ9 to be close to the LQ4 you would be going down in power. The LQ9 has a higher compression ratio than the LQ4 does, you can't program that. I am fairly familiar with ECM tuning.

Your right I did reverse the two motors. My intent was to say with tuning you can get similar HP/Torque numbers out of the Denali tuned vs the Escalade stock. The LQ9 Caddys got different pistons. I was just throwing it out for the original poster that ECMs can be tuned for mileage. I don't have any experience in this area, but I know it made a difference for me going the other route for HP/Torque.

Really interesting. PCM is using a marine variant of the 6.0L motor and claim that it is the most fuel efficient motor every produced for a wakeboard boat.

My Silverado and Tahoe both have 5.3L motors and get about 15MPG combined city and highway just like clockwork. Running on stock diameter tires (on 17's in the Tahoe, on 20's in the truck) the towing is not too bad. You need to keep the revs up when you hit the hills. I run 2nd at 4000-4500RPMs over the Altimont pass routinely at 55-65MPH. Once it drops below 3600 or so you are done, almost no torque in a 5.3 under 4k rpms. California law keeps you in the slow lane or the next one over while towing. This the one time I break that law otherwise it's a big fight to get the boat over the hill. It's worse on the trip back home going into the wind.